1. Field of the Invention
The present invention relates to snap-fit or quick connectors and, more particularly, to quick connectors which are employed in fluid conduit systems to facilitate assembly and disassembly of the fluid conduits.
2. Description of the Art
Snap-fit or quick connectors have been found to be useful in a wide range of applications. In particular, they are frequently employed for joining fluid carrying conduits in automotive and industrial applications. Such connectors have found general acceptance as they are typically capable of being closed in a single uniaxial movement which facilitates automated assembly, and entail simple designs which are relatively inexpensive to produce.
A further advantage of quick connect fittings is that they provide an effective seal for handling volatile or hazardous fluids, such as gasoline, while permitting ease of disassembly and reassembly during repair of a host system. Although tools are often required to effect release of quick connect fittings, squeeze-to-release designs provide for manual release of the fitting without the necessity of separate tools. Although representing an advancement in the art, such "squeeze-to-release" designs often have certain shortcomings.
In applications where hazardous material is to flow through a fitting, prevention of inadvertent release is of primary concern. Accordingly, relatively high axial pull-apart strength specifications are mandated. In order to comply with such specifications, manufacture's of prior art designs typically employed material with a relatively high characteristic flex modulus (such as glass filled Nylon 12) to prevent warping or deformation of abutting locking surfaces within the connector under axial loading conditions. Unfortunately, materials with increased flex modulus are inherently stiffer and can require substantially higher release forces. A related problem is found in that the stiffer material tolerates only relatively short radial displacement of the female connector abutment surface to effect release. This provides relatively little "purchase" (or degree of radial overlap) of the mating abutment surfaces in the engaged condition, thereby exacerbating potential pull apart problems.
Lastly, known prior art designs were prone to fatigue leading to failure after a relatively small number of engagement-disengagement cycles.
The squeeze-to-release quick connector shown in U.S. Pat. No. 5,213,376, assigned to the assignee of the present invention, was designed to overcome these shortcomings. This connector has a pair of parallel arranged beam members, each affixed at one end to a retaining ring and at the other end to a mount located on the outside surface of the body portion of a female connector member. Two or more spaced detents extend inwardly from the retaining ring to capture an abutment surface of a male connector member to effect positive axial engagement between the female and male members. The beam members preferably extend axially a distance approximately equal to the characteristic inner diameter of the body portion of the female member.
The squeeze-to-release quick connector shown in FIG. 1 of U.S. Pat. No. 5,568,946 is similar to the last described quick connector, but further includes a pair of axially extending fingers projecting from each detent toward the bore in the female connector part. The figures are engageable with the abutment on the male connector.
While such squeeze-to-release quick connectors exhibit high pull off forces, certain applications required even higher pull off forces. This led to the development of the squeeze-to-release quick connector with snap-in retainer shown in U.S. Pat. No. 5,568,946. In this connector, a pair of receivers are formed on the female connector housing and receive deflectable latch arms formed on a retainer to releasibly couple the retainer to the housing. Thin tabs extend from a sleeve formed on the retainer to pressure receiving pads which are spaced apart and interconnected by arcuate shaped ring members. A finger extends angularly inward from each pad to engage the abutment on the male connector and to prevent axial disengagement of the male connector from the housing until the fingers are clear of abutment on the male connector displaced radially outward by inward pressure on the pads.
In certain applications, the open end of the quick connector housing is located in a relatively inaccessible position and is closely surrounded or immediately adjacent to other components which make the use of a separate tool to separate the fitting from the female connector or to simply grasp and squeeze the pressure pads on a squeeze-to-release type quick connector relatively difficult if not impossible due to the limited available space. Such limited space factors also make quick connecters with a push-to-release member on one of the connector components difficult to remove from the fitting.
Thus, it would be desirable to provide a quick connector having easily operable means for effecting release of the retainer from the abutment on the male connector part for disengagement of the female and male connector parts. It would be desirable to provide such a quick connector which also has increased end form pull out force.